Panel switch and method for making same

ABSTRACT

A panel switch for use in electronic apparatus and a method for making same, the panel switch employing a diaphragm whereby the operator turns on the switch with a feeling of security. To locate a diaphragm, a sheet having an adhesive layer on one side is used instead of a conventional spacer, and the diaphragm is secured to an insulated substrate with the sheet. The non-use of the spacer saves cost and labor, thereby producing panel switches more economically.

TECHNICAL FIELD

The present invention relates to a panel switch for operating electronicapparatus and a method for making same, and more particularly to a panelswitch for such use, employing a diaphragm in such a manner as to makegood use of its resilient nature whereby the operator operates theswitch with security.

BACKGROUND ART

FIGS. 7 and 8 are a cross-sectional view and an exploded view showing aconventional panel switch. The switch has an insulated substrate 2 onwhich a first contact point 1a and a second contact point 1b are formed.The reference numeral 3 denotes a spacer having a through hole 3a. Thespacer 3 has adhesive layers on opposite sides, and accommodates aspherical or cylindrical resilient metal diaphragm 4. The diaphragm 4 iscovered with an elastic sheet 5. The reference numeral 7 denotes acasing which holds a press button 6. The diaphragm 4 keeps contact withthe second contact point 1b.

For operation, an operator pushes the press button 6 so that thediaphragm 4 is pressed and comes into contact with the contact point 1athrough the sheet 5, thereby effecting electrical connection between thecontact points 1a and 1b by way of the diaphragm 4.

This type of panel switch has the following disadvantages:

One is that the spacer 3 is indispensable for maintaining the diaphragm4 and cannot be omitted. The cost of the spacer is reflected in theproduction cost. Another disadvantage is that the diaphragm 4 must beindividually inserted into the apertures of the spacers 3, therebyconsuming time and labor. In addition, the boring of the aperturesproduces chips, dirt and adhesive remains, which are likely to causepoor contact between the diaphragm 4 and the contact points 1a, 1b.

SUMMARY OF THE INVENTION

In order to solve the problems pointed out above, the present inventionprovides a panel switch capable of economical production. The object isachieved by providing a panel switch which comprises preparing a sheethaving an adhesive layer on one side, attaching a diaphragm to theadhesive layer of the sheet, and attaching the sheet to an insulatedsubstrate, thereby constituting a panel switch.

Thus, there is no need for using a spacer, thereby saving cost andlabor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a panel switch according to thepresent invention;

FIG. 2 is an exploded view showing a main portion of the panel switch ofFIG. 1;

FIG. 3 is a diagrammatic view showing the steps of fabricating a panelswitch according to the present invention;

FIG. 4 is a cross-sectional view showing a modified version of the panelswitch according to the present invention;

FIG. 5 is an exploded view showing a main portion of the panel switch ofFIG. 4;

FIG. 6 is a diagrammatic view showing the steps of fabricating the panelswitch of FIG. 4;

FIG. 7 is a cross-sectional view showing a conventional panel switch;and

FIG. 8 is an exploded view showing a main portion of the conventionalpanel switch of FIG. 7.

DESCRIPTION OF THE BEST MODE OF THE EMBODIMENT

The present invention will be described by way of example shown in thedrawing:

EXAMPLE 1

Referring to FIGS. 1 and 2, the panel switch is provided with aninsulated substrate 12 having contact points 11a, 11b. The panel switchis provided with a spherical or cylindrical resilient metal diaphragm14, which is connected to the contact point 11b. The reference numeral15 denotes an elastic sheet having an adhesive layer on one side. Thesheet 15 is attached to the diaphragm 14 and also to the substrate 12 sothat the diaphragm 14 is united with the substrate 12. The panel switchis provided with a press button 16 held by a casing 17. The button 16 issuspended in such a posture as to be in abutment with the diaphragm 14through the sheet 15. The casing 17 and the press button 16 constitutean operation section.

In operation, an operator presses the press button 16 which then pushesthe diaphragm 14 through the sheet 15. In this way the diaphragm 14comes into contact with the contact point 11a, thereby effectingelectrical connection between the contact points 11a and 11b through thediaphragm. The adhesive to be coated on the sheet 15 should be selectedfrom substances which does not impair the resiliency of the diaphragm14.

Referring to FIG. 3, the process of fabricating the panel switchdescribed above will be described:

FIGS. 3(a), (b), (c), and (d) respectively show a tape having itsreleasable sheet removed, a strip of hoop-like diaphragms to which thetape is attached, tape pieces cut for each unit diaphragm, and aninsulated substrate 12 on which the unit diaphragm is attached. As shownin FIGS. 3(a) to (d), there are prepared a strip of hoop-like diaphragms20, each unit diaphragm 14 being of a spherical or cylindrical shape,and a tape 21 lined with an adhesive layer covered with a protectivereleasable sheet 22. The releasable sheet 22 is designed to protect theadhesive layer of the tape 21 from dirt. The insulated substrate 12 isprovided with several pairs of contact points 11a and 11b. The tape 21will be referred to as the sheet 15 at the later stage.

The panel switch is fabricated in the following manner:

First, the protective releasable tape 22 is removed from the tape 21, soas to attach the tape 21 to the strip of hoop-like diaphragms 20. Thenthe tape 21 is cut into tape pieces for each unit diaphragm 14 as shownin FIG. 3(c). From this stage the tape pieces are referred to as sheets15, and the unit diaphragms 14 are sucked by a vacuum device or anyother similar automatic device, and bridge portions A thereof are cut.Each unit diaphragm 14 is placed on the contact point 11b on thesubstrate 12, and secured to the substrate 12 by the sheet 15. Then thesubstrate 12 with the diaphragm 14 is united with the casing 17 havingthe press button 16. Preferably, after the panel switch is finished, thereleasable tape 22 can be again attached to the tape 21 after it hasbeen joined to the strip of hoop-like diaphragms 20, and removedtherefrom when the unit diaphragms 14 are secured to the insulatedsubstrates 12.

EXAMPLE 2

Referring to FIGS. 4 and 5, wherein like reference numerals correspondto like components in FIGS. 1 and 2 and the description of them isomitted, each diaphragm 14 has a central aperture 25 in the center. Whenthe diaphragm 14 is pressed against the contact point 11a, theperipheral edge of the central aperture 25 is more surely placed incontact with the contact point 11a than otherwise. This secures areliable switch. The reference numeral 26 denotes anadhesion-prohibiting layer formed on the under-surface of the sheet 15by printing or by joining another cover sheet. This adhesion-prohibitinglayer 26 protects the peripheral edge of the central apertures 25 andthe contact point 11a from becoming stained with an adhesive, therebysecuring the contact between the diaphragm 15 and the contact point 11a.In the illustrated embodiment a band type of adhesion-prohibiting layer26 is used, but the shape is not limited to it if theadhesion-prohibiting layers 26 can cover the respective centralapertures 25. Instead of using the adhesion-prohibiting layer 26, analternative method is to dispense with the coating of an adhesive at thespots of diaphragm that correspond to the central apertures 25. When theadhesion-prohibiting layer 26 of a band type is used, the advantage isthat the air trapped in the diaphragm 14 is allowed to escape when thediaphragm 14 is pressed against the contact point 11a, thereby enablingthe operator to feel assured of the operability of the switch.

Referring to FIG. 6, the process of fabricating the example illustratedin FIGS. 4 and 5 will be described:

FIGS. 6(a), (b), (c), and (d) respectively show a tape having itsreleasable sheet removed and having the adhesion-prohibiting tape 26attached, a strip of hoop-like diaphragms 20 to which the tape isattached, tape pieces cut for each unit diaphragm 14, and an insulatedsubstrate 12 on which the unit diaphragm 14 is attached to the substrate12. In FIG. 6 like reference numerals indicate like components in FIG. 3and FIGS. 4, 5, and the description of these components will be omittedfor simplicity. As shown in FIGS. 6(a) to (d), the tape 21 is providedwith an adhesion-prohibiting layer 27 having a smaller width than thatof the tape 21, and is attached to the tape 21 so as to cover therespective central apertures 25 of each of the unit diaphragms 14 whenthe tape 21 is overlaid on the strip of hoop-like diaphragms. Instead ofusing the adhesion-prohibiting layer 27, an alternative way is to coverthe adhesive layer by printing or with any other medium.

INDUSTRIAL APPLICABILITY

As evident from the foregoing description, the diaphragm is secured tothe insulated substrate with the sheet without the use of any spacer.The non-use of the spacer saves the cost and labor, thereby providing aneconomical panel switch. The diaphragm is prepared in a continuous hoop,and after the adhesive tape is attached thereto, the diaphragm is cutinto units, and the unit diaphragms each are covered with the sheetswhich are secured to the insulated substrate. As a result, the followingadvantages have been achieved:

(1) Until the unit diaphragm is sucked by an automatic device, it iskept continuous as a hoop, thereby avoiding the production of panelswitches having two diaphragms attached to.

(2) Since the diaphragms are individually united with the casings, thesame process can be applied regardless of variations in the optionalarrangement of keys on equipment.

(3) The method of the invention eliminates the use of any spacer, andeach diaphragm is independent of each other. Thus, modifications andvariations in design and shape can be freely done, thereby speeding upthe production and saving on the cost.

We claim:
 1. A process for making a panel switch, the process comprisingthe steps of joining a tape having an adhesive layer on one side to astrip of resilient hoop-like diaphragms, cutting the strip of diaphragmsinto units such that each of the diaphagm units is individually coveredby a separate adhesive sheet, and securing each diaphragm unit to aninsulated substrate having electrical contact points, said diaphragmunits serving as actuators to make electrical contact with saidelectrical contact points of said substrate.